摘要
Based on MC-ICP-MS U-series dating and stable O-isotope analysis results, a 4―5 years resolution monsoon record over the past 1000 years has been estab- lished for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ 18O record with the ?14C record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ 18O value at AD 1720 indicates an abrupt increase in monsoon rainfall, sug- gesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.
Based on MC-ICP-MS U-series dating and stable O-isotope analysis results, a4-5 years resolution monsoon record over the past 1000 years has been established for twostalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxyfor variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A closerelation of the delta^(18)O record with the triangle open ^(14)C record from tree rings largelyreflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuousdecrease in the delta^(18)O value at AD 1720 indicates an abrupt increase in monsoon rainfall,suggesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important rolein rapid increase of the Northern Hemisphere temperature over the last century.
基金
This work was supported by the National Outstanding Youth Foundation of China(Grant No.40225007)
the 973 Project(Grant No.2004CB20204).
关键词
贵州
地质研究
溶洞
石笋
氧同位素
cave stalagmite
oxygen isotope
southwest monsoon
solar activity
Guizhou